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Sunday, April 3, 2011

Heart Failure

A 68-year-old woman is hospitalized with palpitations and shortness of breath. She has a history of hypertension and chronic atrial fibrillation, and her medications are furosemide, candesartan, and warfarin. On physical examination, the heart rate is 120/min with an irregularly irregular rhythm, and blood pressure is 130/80 mm Hg with no evidence of pulsus paradoxus. She has an elevated jugular venous pressure with normal x and y descent, crackles in both lungs, and marked lower extremity edema. Echocardiography shows left ventricular hypertrophy, an ejection fraction of 70%, and no significant valvular disease.

After intravenous diuretics are begun, the patient's symptoms improve, and the crackles and peripheral edema resolve. Her heart rate is now 99/min, and her blood pressure is 120/75 mm Hg.

Which of the following is the most likely primary mechanism of her heart failure? A Constrictive pericarditis B Diastolic dysfunction C Systolic dysfunction D Valvular disease

Key PointThe diagnosis of diastolic heart failure is generally made when signs and symptoms of systolic heart failure are present but the echocardiogram shows a normal left ventricular ejection fraction and an absence of significant valvular abnormalities.

Answer and Critique (Correct Answer = B)

This patient has a history and echocardiographic findings consistent with diastolic dysfunction. She has hypertension, which predisposes to the development of left ventricular hypertrophy and associated impaired ventricular relaxation.

Although she presented with evidence of heart failure, the echocardiogram demonstrated normal systolic function and no significant valvular abnormalities that could account for the heart failure. Therefore, systolic dysfunction and valvular disease are unlikely. Constrictive pericarditis is also unlikely in the absence of pulsus paradoxus, normal x and y descent, and no echocardiographic evidence of constrictive pericarditis, such as pericardial thickening or abrupt posterior motion of the ventricular septum in early diastole with inspiration.

The primary treatment goals in patients with diastolic heart failure are to treat the underlying cause (if possible), manage any potentially exacerbating factors, and optimize diastolic filling by slowing the heart rate with β-blockers. To date, there have been no medications shown to reduce morbidity and mortality in patients with diastolic dysfunction.Bibliography